Field of the Invention
The present invention relates to a tool for grinding concrete, asphalt, marble, etc., and more particularly, to a grinding tool capable of adjusting cutting force, service life, dust, etc. in a single plate.
Description of the Related Art
In general, grinding tools are mainly used in the processes of grinding concrete, asphalt, artificial stone, natural stone, granite, marble, etc., or removing coating layers, etc., while rotating at high speed.
Grinding tools can be classified according to a structure in which a shoe having a grinding tip is directly fastened to a plate, a structure in which a shoe having a grinding tip is coupled to a holder in the state of fixing the holder to a plate, and the like.
Since the grinding tip formed in the shoe is gradually worn down according to the progress of grinding, it is necessary to replace the shoe at some point.
FIG. 1 is a view illustrating an example of a grinding tool in which shoes are coupled to a plate.
In FIG. 1, in order to couple shoes 5, in which grinding tips are arranged, to a plate 1 coupled to a drive unit through coupling holes 30, holders 5 are formed in the plate, and support pieces 4 formed in the shoes 2 are coupled to the plate 1.
The support pieces 4 are formed at both sides of each shoe 2, the plate 1 is formed with support piece coupling grooves 5 to which the support pieces 4 of the shoe 2 are coupled. In addition, a Velcro 3 is formed between the support piece coupling grooves 5 at a position corresponding to the inner surface of the shoe 2, such that a cushion is added and adhered to the shoe 2 with a rubber pad interposed therebetween.
In the case illustrated in FIG. 1, the shoes may be fastened to the plate only in one direction. As a result, all the grinding tips are arranged in a regular pattern, as illustrated in FIG. 1.
Besides, in the case where shoes having grinding tips are directly fastened to a plate, the shoes are fastened to the plate only in one direction. That is, all fronts of the grinding tips have a single shape when each shoe is viewed from the center of the plate in the state in which the shoes having the grinding tips are fastened to the plate.
FIG. 2 is a view illustrating an example in which grinding tips are arranged on a shoe. Herein, (a) of FIG. 2 illustrates the state in which the grinding tips are close to each other in the forward rotation direction, and (b) of FIG. 2 illustrates the state in which the grinding tips are spaced apart from each other in the forward rotation direction.
In FIG. 2, the grinding tips are arranged such that a grinding tip 20a located outward on the shoe forms an angle of approximately 20 to 60° with a grinding tip 20b located inward on the shoe. In the arrangement of the grinding tips illustrated in FIG. 2, the grinding tips have a long life due to an outside large area on the shoe, and have effects of collecting dust (see (a) of FIG. 2) and of raising dust (see (b) of FIG. 2) when the plate rotates.
FIG. 3 is a view illustrating another example in which grinding tips are arranged in almost parallel with each other on a shoe. In (a) of FIG. 3, the outside sides of the grinding tips are located further forward than the inside sides thereof in the rotation direction. However, (b) of FIG. 3 illustrates a case opposite to the above state.
In FIG. 3, the grinding tips are provided such that grinding tips 20c and 20d, which are located at respective front and rear in the rotation direction of a plate, are arranged in almost parallel with each other. In the arrangement of the grinding tips illustrated in FIG. 3, the grinding tips have high cutting force.
Only one grinding tip is typically arranged in one plate. However, in order to realize various arrangements of the grinding tips in one plate as illustrated in (a) and (b) of FIG. 2, and (a) and (b) of FIG. 3, the grinding tips have to be arranged in different forms on the shoe. For this reason, productivity is deteriorated.
As the related art, Korean Patent No. 10-0816026 (Mar. 21, 2008) discloses a grinding wheel assembly of a dry grinder.